Application to hippocampus and serum samples from APP/PS1 transgenic Alzheimer’s disease mice revealed significantly higher AβO levels and decreased Fetuin B levels compared to healthy controls, supporting the link between AβO and early AD pathology, as well as inflammation-related suppression of Fetuin B. Recovery values ranged from 98.0–100.9% for AβO in hippocampus, 98.9–109.8% for AβO in serum, and 97.7–106.7% for Fetuin B in serum (all RSD < 5%). The gene discussed is FETUB; the disease is early-onset autosomal dominant Alzheimer disease.